Table-top power tools are used in a wide variety of applications including wood working and metal working. Table-top power tools are typically mounted to a flat work surface, the table, configured to accept and guide work piece to the table-top tool. These power tools allow users to operate with more precision on larger work pieces than allowed with hand-held power tools. While table-top power tools are mounted to the table, the angle and position of the tool may be adjusted during operation. Some table-top power tools use one or more pull rods to change the position of the table top tool.
An example of a table-top power tool using a pull rod is a table saw which includes a circular saw blade. The circular saw blade extends through the table top surface, and a work piece, typically a piece of wood, is placed on the table top for cutting. The saw blade assembly is mounted on rails running along the length of the table, and the saw blade may be pushed or pulled along the rails in response to pushing or pulling on the pull rod. If the saw is activated, the spinning saw blade cuts through work pieces placed in its path on the table. In some existing table saws, the pull rod is also used to adjust the height of the circular saw blade. This adjustment is carried out by rotating the pull rod along its longitudinal axis in either a clockwise or counter-clockwise direction. The rotation of the pull rod increases and decreases the height of the saw blade above the table surface, depending upon the direction of rotation of the pull rod.
The pull rod may also be configured to lock the blade in a fixed position relative to table top in order to provide a rip saw mode of operation. In the rip saw mode, the pull rod locks the circular saw blade into a fixed position on the rails, and the work piece may then be moved over the saw-blade to cut the work piece.
The pull rod may also be configured to lock itself and the circular saw blade in place to allow for safety and/or transportation of the table saw with the blade in a secured position. Existing pull rods that are locked into position require two or more steps to unlock. For example, some known pull rod assemblies require a central button to be pushed in while simultaneously pulling outward on the pull rod to unlock it. These pull rod assemblies are generally difficult for an operator to unlock.
In view of the foregoing, it would be advantageous to provide a locking and unlocking mechanism for a pull rod assembly that permits unlocking the pull rod using fewer motions than traditional pull rod assemblies. It would also be advantageous to provide a locking and unlocking mechanism for a pull rod assembly configured to unlock the pull rod using few motions while permitting the pull rod to rotate on its longitudinal axis.